CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
CURRENT ASSETS:
Cash and cash equivalents	$ 69,791	$ 170,636
Marketable securities	384,944	487,239
Restricted cash	12,220	12,219
Income tax receivable	1,004	840
Receivables, net	118,584	111,186
Inventories, net	145,667	138,094
Prepaid aircraft rents	408,781	360,781
Deferred tax assets	155,849	156,050
Other current assets	18,880	27,392
Total current assets	1,315,720	1,464,437
PROPERTY AND EQUIPMENT:
Aircraft and rotable spares	4,346,323	4,080,886
Deposits on aircraft	40,000	40,000
Buildings and ground equipment	288,038	279,965
Total property and equipment, gross	4,674,361	4,400,851
Less-accumulated depreciation and amortization	(1,835,386)	(1,749,058)
Total property and equipment, net	2,838,975	2,651,793
OTHER ASSETS
Intangible assets, net	13,873	14,998
Other assets	111,273	101,991
Total other assets	125,146	116,989
Total assets	4,279,841	4,233,219
CURRENT LIABILITIES:
Current maturities of long-term debt	192,415	177,389
Accounts payable	260,441	245,518
Accrued salaries, wages and benefits	131,620	133,002
Accrued aircraft rents	2,261	7,492
Taxes other than income taxes	18,059	19,626
Other current liabilities	41,030	37,437
Total current liabilities	645,826	620,464
OTHER LONG-TERM LIABILITIES	73,609	76,305
LONG-TERM DEBT, net of current maturities	1,377,306	1,293,179
DEFERRED INCOME TAXES PAYABLE	717,727	727,358
DEFERRED AIRCRAFT CREDITS	77,082	80,974
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY:
Preferred stock, 5,000,000 shares authorized; none issued
Common stock, no par value, 120,000,000 shares authorized; 77,728,758 and 77,325,702 shares issued, respectively	621,956	618,511
Retained earnings	1,156,074	1,197,819
Treasury stock, at cost, 26,765,386 and 26,095,636 shares, respectively	(391,364)	(382,950)
Accumulated other comprehensive income	1,625	1,559
Total stockholders' equity	1,388,291	1,434,939
Total liabilities and stockholders' equity	$ 4,279,841	$ 4,233,219